Terrego is a large storm complex with a length of 400 km. The event is moving rapidly across the country and may bring hurricane-like winds, heavy rain and thunderstorms. This type of weather is more common in the interior of the United States, but sky discoloration is rare.
Calm before the storm
According to the National Weather Service (NWS), US KNMI, the sky changes color before a rain break or sometimes during a storm. According to Peter Rogers, a meteorologist with the NWS, this is due to the way the sun shines on certain particles in the atmosphere. The New York Times†
“It must have gotten a lot of attention,” Rogers says. Green skies were mostly seen in and around downtown Sioux Falls, where many residents filmed the event and posted it on social media.
According to the NWS, the color green can indicate hail is on the way. It didn’t happen much, but it rained in some places. In the neighboring state of Minnesota, a baseball-sized hailstone was discovered.
A strong wind blows
The terrego brought strong winds, reaching nearly 100 miles per hour in some places. The total damage was not known, but there were no casualties near Sioux Falls, where the sky turned green. However, some buildings, trees and power cables were damaged.
Central American states, collectively referred to as the Great Plains, are more likely to experience similar weather events. In the summer of 2020, a terrego caused massive damage. 250,000 people were left without power, resulting in four deaths.